Setting Scale

The size of your setting is entirely up to you! Be warned that readers probably only want details of the places that affect the main characters. It's great that there is some small jungle island, full of danger and peril, braved by explorers only for its world renowned peaches; but if the main characters are surfers who couldn't give a damn about peaches, there's no reason to bring it up; unless the North beach has some gnarly swells dude.

Here is some sort of reference scale for setting size:

• house - probably enough for a short story. not necessarily a house, but a house-sized area with several details. (could include stores, playgrounds, classrooms, offices etc.)
• neighborhood - usually enough for a single novel. think maybe a 3 mile radius, probably a few "houses" included. there may be some theme to the "neighborhood". (could be a school campus, dorm, hospital, office building)
• city - might be enough for a series. a "city" includes a collection of "neighborhoods." could be several miles in radius. (perhaps a castle and surrounding farms, or a settlement on a new planet)
• country - while a "city" may have its own culture, a country most likely does. a country also is likely friends and enemies with other countries. settings this scale and larger are usually recognized when war/espionage/grand  adventure is the binding plot. 

Sure we could go on to global, interplanetary and interstellar scales, but I'm hoping you understand my meaning.